"Genre
is a French term derived from the Latin genus, generis,
meaning "type", "sort" or "kind."
It designates the literary form or type into which works
are classified according to what they have in common,
either in their formal structures or in their treatment
of subject matter, or both."http://academic.brooklyn.cuny.edu/english/melani/cs6/genres

Remember
- Sub-Genres are classifications used to help categorize
a novel in the marketplace, or to assist readers in
finding similar books in styles they already enjoy.
However, many authors will happily combine two or more
sub-genre styles within the one plot. As these cross-genre
books become more popular, this creates sub-categories
within sub-genres.

Fantasy Sub-Genres
by Lee Masterson
In recent times, the term 'fantasy', when regarded as
part of an individual genre, generally brings to mind
tales of dragons and castles and knights in shining armor
- but in truth, the genre as a whole encompasses so much
more.

Horror Sub-Genres
by Paula Guran
From H.P Lovecraft to Stephen King, horror is still a
popular genre and growing. The broad term 'horror' covers
only the trunk of the tree, but there are many, many
branches, called sub-genres, that also fall into this
classification.

Romance Sub-Genresby Lee
Masterson
The Romance Genre has broken off into so many separate
branches that several distinct sub-genres were formed to
cater to the varying tastes of discerning women.

Science Fiction Sub-Genres
by Lee MastersonIn
recent times, science fiction has evolved from the 'pulp-futuristic'
tale, into a whole unique genre. The broad term 'science
fiction' covers only the trunk of the tree, but there are
many, many branches, called sub-genres, that also fall
into this classification.